Directions:

Step 1 – In a medium bowl, whisk vinegar, syrup, mustard, and 3/4 teaspoon salt. While whisking, slowly pour in oil until combined.

Step 2 – Place chicken between 2 pieces of plastic wrap and pound with a meat mallet into 1/2″-thick pieces. Transfer chicken to a large bowl; season all over with Italian seasoning, 3/4 teaspoon salt, and 1/4 teaspoon pepper. Pour 1/4 cup balsamic dressing over chicken; refrigerate remaining dressing until ready to use. Turn chicken to coat and let marinate, tossing a few times, at least 15 minutes at room temperature, or cover bowl and refrigerate up to 3 hours.

Step 3 – Prepare a grill for medium-high heat; heat 5 minutes (or preheat a grill pan over medium-high heat). Grill chicken, turning halfway through, until golden brown and just cooked through, about 5 minutes per side. Transfer to a cutting board and let cool slightly.

Step 4 – Meanwhile, divide lettuce, avocado, mozzarella, tomatoes, and basil among bowls. Thinly slice chicken and arrange in bowls. Drizzle with reserved dressing.